heathen (n.) Look up heathen at Dictionary.com
Old English hæðen "not Christian or Jewish," also as a noun, "heathen man" (especially of the Danes), merged with Old Norse heiðinn (adj.) "heathen, pagan;" perhaps literally "pertaining to one inhabiting uncultivated land;" see heath + -en (2).

But historically assumed to be from Gothic haiþno "gentile, heathen woman," used by Ulfilas in the first translation of the Bible into a Germanic language (as in in Mark vii:26, for "Greek"); if so it could be a derivative of Gothic haiþi "dwelling on the heath," but this sense is not recorded. It may have been chosen on model of Latin paganus, with its root sense of "rural" (see pagan), or for resemblance to Greek ethne (see gentile), or it may be a literal borrowing of that Greek word, perhaps via Armenian hethanos [Sophus Bugge]. Like other basic words for exclusively Christian ideas (such as church) it likely would have come first into Gothic and then spread to other Germanic languages.